/* Copyright (C) 2011, 2012, 2013 by Bundesanstalt für Gewässerkunde
 * Software engineering by Intevation GmbH
 *
 * This file is Free Software under the GNU AGPL (>=v3)
 * and comes with ABSOLUTELY NO WARRANTY! Check out the
 * documentation coming with Dive4Elements River for details.
 */

package org.dive4elements.river.artifacts.services;

import java.awt.BasicStroke;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Transparency;
import java.awt.geom.Rectangle2D;
import java.awt.image.BufferedImage;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

import javax.imageio.ImageIO;

import org.apache.log4j.Logger;
import org.dive4elements.artifactdatabase.DefaultService;
import org.dive4elements.artifacts.CallMeta;
import org.dive4elements.artifacts.GlobalContext;
import org.dive4elements.artifacts.Service;
import org.dive4elements.river.artifacts.model.FixingsColumn;
import org.dive4elements.river.artifacts.model.FixingsColumnFactory;
import org.dive4elements.river.artifacts.model.FixingsFilterBuilder;
import org.dive4elements.river.artifacts.model.FixingsOverview;
import org.dive4elements.river.artifacts.model.FixingsOverview.Fixing;
import org.dive4elements.river.artifacts.model.FixingsOverviewFactory;
import org.dive4elements.river.artifacts.model.GaugeFinder;
import org.dive4elements.river.artifacts.model.GaugeFinderFactory;
import org.dive4elements.river.artifacts.model.GaugeRange;
import org.dive4elements.river.artifacts.model.fixings.QWI;
import org.dive4elements.river.artifacts.resources.Resources;
import org.dive4elements.river.backend.SessionHolder;
import org.dive4elements.river.jfree.ShapeRenderer;
import org.dive4elements.river.utils.Formatter;
import org.dive4elements.river.utils.Pair;
import org.jfree.chart.ChartFactory;
import org.jfree.chart.JFreeChart;
import org.jfree.chart.LegendItemCollection;
import org.jfree.chart.axis.NumberAxis;
import org.jfree.chart.plot.Marker;
import org.jfree.chart.plot.PlotOrientation;
import org.jfree.chart.plot.ValueMarker;
import org.jfree.chart.plot.XYPlot;
import org.jfree.data.Range;
import org.jfree.ui.RectangleAnchor;
import org.jfree.ui.TextAnchor;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NodeList;

/** Serve chart of Fixings at certain km. */
public class FixingsKMChartService extends DefaultService {
    private static final Logger log = Logger.getLogger(FixingsKMChartService.class);

    public static final int DEFAULT_WIDTH = 240;
    public static final int DEFAULT_HEIGHT = 180;

    public static final String[] I18N_Q_SECTOR_BOARDERS = { "fix.km.chart.q.sector.border0", "fix.km.chart.q.sector.border1", "fix.km.chart.q.sector.border2" };

    public static final String[] DEFAULT_Q_SECTOR_BORDERS = { "(MNQ + MQ)/2", "(MQ + MHQ)/2", "HQ5" };

    public static final String I18N_CHART_LABEL_DATE = "fix.km.chart.label.date";

    public static final String DEFAULT_CHART_LABEL_DATE = "yyyy/MM/dd";

    public static final String I18N_CHART_TITLE = "fix.km.chart.title";

    public static final String DEFAULT_CHART_TITLE = "Fixings {0} km {1,number,#.###}";

    public static final String I18N_Q_AXIS = "common.export.csv.header.q";

    public static final String DEFAULT_Q_AXIS = "Q [m\u00b3/s]";

    public static final String I18N_W_AXIS = "fix.km.chart.w.axis";

    public static final String DEFAULT_W_AXIS = "W [NN + m]";

    public static final String I18N_MEASURED = "fix.km.chart.measured";

    public static final String DEFAULT_MEASURED = "measured";

    public static final String I18N_INTERPOLATED = "fix.km.chart.interpolated";

    public static final String DEFAULT_INTERPOLATED = "interpolated";

    public static final String DEFAULT_FORMAT = "png";

    // TODO: Load fancy image from resources.
    public static final byte[] EMPTY = { (byte) 0x89, (byte) 0x50, (byte) 0x4e, (byte) 0x47, (byte) 0x0d, (byte) 0x0a, (byte) 0x1a, (byte) 0x0a, (byte) 0x00,
            (byte) 0x00, (byte) 0x00, (byte) 0x0d, (byte) 0x49, (byte) 0x48, (byte) 0x44, (byte) 0x52, (byte) 0x00, (byte) 0x00, (byte) 0x00, (byte) 0x01,
            (byte) 0x00, (byte) 0x00, (byte) 0x00, (byte) 0x01, (byte) 0x08, (byte) 0x00, (byte) 0x00, (byte) 0x00, (byte) 0x00, (byte) 0x3a, (byte) 0x7e,
            (byte) 0x9b, (byte) 0x55, (byte) 0x00, (byte) 0x00, (byte) 0x00, (byte) 0x01, (byte) 0x73, (byte) 0x52, (byte) 0x47, (byte) 0x42, (byte) 0x00,
            (byte) 0xae, (byte) 0xce, (byte) 0x1c, (byte) 0xe9, (byte) 0x00, (byte) 0x00, (byte) 0x00, (byte) 0x09, (byte) 0x70, (byte) 0x48, (byte) 0x59,
            (byte) 0x73, (byte) 0x00, (byte) 0x00, (byte) 0x0b, (byte) 0x13, (byte) 0x00, (byte) 0x00, (byte) 0x0b, (byte) 0x13, (byte) 0x01, (byte) 0x00,
            (byte) 0x9a, (byte) 0x9c, (byte) 0x18, (byte) 0x00, (byte) 0x00, (byte) 0x00, (byte) 0x07, (byte) 0x74, (byte) 0x49, (byte) 0x4d, (byte) 0x45,
            (byte) 0x07, (byte) 0xdc, (byte) 0x04, (byte) 0x04, (byte) 0x10, (byte) 0x30, (byte) 0x15, (byte) 0x7d, (byte) 0x77, (byte) 0x36, (byte) 0x0b,
            (byte) 0x00, (byte) 0x00, (byte) 0x00, (byte) 0x08, (byte) 0x74, (byte) 0x45, (byte) 0x58, (byte) 0x74, (byte) 0x43, (byte) 0x6f, (byte) 0x6d,
            (byte) 0x6d, (byte) 0x65, (byte) 0x6e, (byte) 0x74, (byte) 0x00, (byte) 0xf6, (byte) 0xcc, (byte) 0x96, (byte) 0xbf, (byte) 0x00, (byte) 0x00,
            (byte) 0x00, (byte) 0x0a, (byte) 0x49, (byte) 0x44, (byte) 0x41, (byte) 0x54, (byte) 0x08, (byte) 0xd7, (byte) 0x63, (byte) 0xf8, (byte) 0x0f,
            (byte) 0x00, (byte) 0x01, (byte) 0x01, (byte) 0x01, (byte) 0x00, (byte) 0x1b, (byte) 0xb6, (byte) 0xee, (byte) 0x56, (byte) 0x00, (byte) 0x00,
            (byte) 0x00, (byte) 0x00, (byte) 0x49, (byte) 0x45, (byte) 0x4e, (byte) 0x44, (byte) 0xae, (byte) 0x42, (byte) 0x60, (byte) 0x82 };

    private static final Output empty() {
        return new Output(EMPTY, "image/png");
    }

    @Override
    public Service.Output process(final Document data, final GlobalContext globalContext, final CallMeta callMeta) {
        log.debug("FixingsKMChartService.process");

        SessionHolder.acquire();
        try {
            return doProcess(data, globalContext, callMeta);
        } finally {
            SessionHolder.release();
        }
    }

    protected Service.Output doProcess(final Document input, final GlobalContext globalContext, final CallMeta callMeta) {
        final String river = getRiverName(input);
        final Double km = getKM(input);
        final Dimension extent = getExtent(input);
        final String format = getFormat(input);

        if (river == null || km == null) {
            log.warn("River and/or km invalid.");
            return empty();
        }

        final FixingsOverview overview = FixingsOverviewFactory.getOverview(river);

        if (overview == null) {
            log.warn("No overview found for river '" + river + "'");
            return empty();
        }

        final FixingsFilterBuilder ffb = new FixingsFilterBuilder(input);

        final List<Fixing.Column> columns = overview.filter(ffb.getRange(), ffb.getFilter());

        final List<Pair<Fixing.Column, FixingsColumn>> cols = new ArrayList<>();

        for (final Fixing.Column col : columns) {
            final FixingsColumn data = FixingsColumnFactory.INSTANCE.getColumnData(col);
            if (data != null) {
                cols.add(new Pair<>(col, data));
            }
        }

        final JFreeChart chart = createChart(cols, river, km, callMeta);

        return encode(chart, extent, format);
    }

    protected static Output encode(final JFreeChart chart, final Dimension extent, final String format) {
        final BufferedImage image = chart.createBufferedImage(extent.width, extent.height, Transparency.BITMASK, null);

        final ByteArrayOutputStream out = new ByteArrayOutputStream();

        try {
            ImageIO.write(image, format, out);
        }
        catch (final IOException ioe) {
            log.warn("writing image failed", ioe);
            return empty();
        }

        return new Output(out.toByteArray(), "image/" + format);
    }

    protected static JFreeChart createChart(final List<Pair<Fixing.Column, FixingsColumn>> cols, final String river, final double km, final CallMeta callMeta) {
        final String labelFormat = Resources.getMsg(callMeta, I18N_CHART_LABEL_DATE, DEFAULT_CHART_LABEL_DATE);

        final QWSeriesCollection.LabelGenerator lg = new QWSeriesCollection.DateFormatLabelGenerator(labelFormat);

        final QWSeriesCollection dataset = new QWSeriesCollection(lg);

        final double[] w = new double[1];
        for (final Pair<Fixing.Column, FixingsColumn> col : cols) {
            final boolean interpolated = !col.getB().getW(km, w);
            final double q = col.getB().getQ(km);
            if (!Double.isNaN(w[0]) && !Double.isNaN(q)) {
                final QWI qw = new QWI(q, w[0], col.getA().getDescription(), col.getA().getStartTime(), interpolated, 0);
                dataset.add(qw);
            }
        }

        final String title = Resources.format(callMeta, I18N_CHART_TITLE, DEFAULT_CHART_TITLE, river, km);

        final String qAxis = Resources.getMsg(callMeta, I18N_Q_AXIS, DEFAULT_Q_AXIS);

        final String wAxis = Resources.getMsg(callMeta, I18N_W_AXIS, DEFAULT_W_AXIS);

        final JFreeChart chart = ChartFactory.createXYLineChart(title, qAxis, wAxis, null, PlotOrientation.VERTICAL, true, true, false);

        final XYPlot plot = (XYPlot) chart.getPlot();

        final NumberAxis qA = (NumberAxis) plot.getDomainAxis();
        qA.setNumberFormatOverride(Formatter.getWaterlevelQ(callMeta));

        final NumberAxis wA = (NumberAxis) plot.getRangeAxis();
        wA.setNumberFormatOverride(Formatter.getWaterlevelW(callMeta));

        plot.setRenderer(0, dataset.createRenderer());
        plot.setDataset(0, dataset);

        final Rectangle2D area = dataset.getArea();

        if (area != null) {
            final double height = area.getHeight();
            final double wInset = Math.max(height, 0.01) * 0.25d;

            wA.setAutoRangeIncludesZero(false);
            wA.setRange(new Range(area.getMinY() - wInset, area.getMaxY() + wInset));
        }

        final String measuredS = Resources.getMsg(callMeta, I18N_MEASURED, DEFAULT_MEASURED);

        final String interpolatedS = Resources.getMsg(callMeta, I18N_INTERPOLATED, DEFAULT_INTERPOLATED);

        final LegendItemCollection lic = plot.getLegendItems();
        dataset.addLegendItems(lic, new ShapeRenderer.LabelGenerator() {
            @Override
            public String createLabel(final ShapeRenderer.Entry entry) {
                return entry.getFilled() ? measuredS : interpolatedS;
            }
        });
        plot.setFixedLegendItems(lic);

        applyQSectorMarkers(plot, river, km, callMeta);

        chart.setBackgroundPaint(Color.white);
        plot.setBackgroundPaint(Color.white);
        plot.setDomainGridlinePaint(Color.gray);
        plot.setRangeGridlinePaint(Color.gray);
        plot.setDomainGridlinesVisible(true);
        plot.setRangeGridlinesVisible(true);

        return chart;
    }

    /** Add domain markers to plot that indicate Q-sectors. */
    protected static void applyQSectorMarkers(final XYPlot plot, final String river, final double km, final CallMeta meta) {
        final GaugeFinderFactory ggf = GaugeFinderFactory.getInstance();
        final GaugeFinder gf = ggf.getGaugeFinder(river);

        if (gf == null) {
            log.warn("No gauge finder found for river '" + river + "'");
            return;
        }

        final GaugeRange gr = gf.find(km);
        if (gr == null) {
            log.debug("No gauge range found for km " + km + " on river " + river + ".");
            return;
        }

        if (log.isDebugEnabled()) {
            log.debug(gr);
        }

        for (int i = 0; i < I18N_Q_SECTOR_BOARDERS.length; ++i) {
            final String key = I18N_Q_SECTOR_BOARDERS[i];
            final String def = DEFAULT_Q_SECTOR_BORDERS[i];
            final String label = Resources.getMsg(meta, key, def);

            final Marker m = createQSectorMarker(gr.getSectorBorder(i), label);

            if (m != null) {
                plot.addDomainMarker(m);
            }
        }
    }

    /** Create Marker at value with label. */
    protected static Marker createQSectorMarker(final double value, final String label) {
        if (Double.isNaN(value)) {
            return null;
        }
        final Marker m = new ValueMarker(value);
        m.setPaint(Color.black);
        m.setStroke(new BasicStroke());
        m.setLabel(label);
        m.setLabelAnchor(RectangleAnchor.TOP_LEFT);
        m.setLabelTextAnchor(TextAnchor.TOP_LEFT);
        return m;
    }

    protected static String getRiverName(final Document input) {
        final NodeList rivers = input.getElementsByTagName("river");

        if (rivers.getLength() == 0) {
            return null;
        }

        final String river = ((Element) rivers.item(0)).getAttribute("name");

        return river.length() > 0 ? river : null;
    }

    protected static Double getKM(final Document input) {
        final NodeList kms = input.getElementsByTagName("km");

        if (kms.getLength() == 0) {
            return null;
        }

        final String km = ((Element) kms.item(0)).getAttribute("value");

        try {
            return Double.valueOf(km);
        }
        catch (final NumberFormatException nfe) {
            log.warn("Km '" + km + " is not a valid number.");
            return null;
        }
    }

    protected static Dimension getExtent(final Document input) {

        int width = DEFAULT_WIDTH;
        int height = DEFAULT_HEIGHT;

        final NodeList extents = input.getElementsByTagName("extent");

        if (extents.getLength() > 0) {
            final Element element = (Element) extents.item(0);
            final String w = element.getAttribute("width");
            final String h = element.getAttribute("height");

            try {
                width = Math.max(1, Integer.parseInt(w));
            }
            catch (final NumberFormatException nfe) {
                log.warn("width '" + w + "' is not a valid.");
            }

            try {
                height = Math.max(1, Integer.parseInt(h));
            }
            catch (final NumberFormatException nfe) {
                log.warn("height '" + h + "' is not a valid");
            }
        }

        return new Dimension(width, height);
    }

    protected static String getFormat(final Document input) {
        String format = DEFAULT_FORMAT;

        final NodeList formats = input.getElementsByTagName("format");

        if (formats.getLength() > 0) {
            final String type = ((Element) formats.item(0)).getAttribute("type");
            if (type.length() > 0) {
                format = type;
            }
        }

        return format;
    }
}
// vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :